Apparatus for an infinite change of the vertical movement of the specimen in microtomes and ultramicrotomes

ABSTRACT

Microtomes utilizing a specimen holder having alternate motion with respect to the knife are improved by adjustment means permitting the distance traversed by the specimen holder to be changed dependent upon the size and type of the specimen as well as its location in the specimen holder. The specimen holder is traversed by linkage including a pivotable rocker arm having oscillating motion and a slidable link mounted thereon transferring the alternate motion of the rocker arm to the specimen holder. The distance traversed by the specimen holder is set by adjusting the distance between the slidable link and the pivot point of the rocker arm.

United States Patent Sitte 1 Oct. 15, 1974 APPARATUS FOR AN INFINITE CHANGE Hellmuth Sitte, l-lomburg/Saar, Germany C. Reichert Optische Werke AG, Vienna, Austria Filed: Nov. 10, 1972 Appl. No; 305,618

Inventor:

Int. Cl B26d 1/02, B26d'7/06 Field of Search 83/703, 707, 411 R, 915.5, 83/414, 410

References Cited UNITED STATES PATENTS 2/1958 Blum 83/410 8/1960 Blum 83/410 US. Cl. 83/703, 83/410 7 3,496,819 2/1970 Blum 83/9155 X Primary ExaminerWillie G. Abercrombie Attorney, Agent, or Firm--Alan H. Spencer; William C. Nealon [57] ABSTRACT Microtomes utilizing a specimen holder having alternate motion with respect to the knife are improved by adjustment means permitting the distance traversed by the specimen holder to be changed dependent upon the size and type of the specimen as well as its location in the specimen holder. The specimen holder is traversed by linkage including a pivotable rocker arm having oscillating motion and a slidable link mounted thereon transferring the alternate motion of the rocker arm to the specimen holder. The distance traversed by the specimen holder is set by adjusting the distance between the slidable link and the pivot point of the rocker arm.

4 Claims, 3 Drawing Figures PAIENIEI] um I 51974 SHEET 10F 2 FIG].

PAIENIEU [ET I 51374 SHE 2 OF 2 APPARATUS FOR AN INFINITE CHANGE OF THE VERTICAL MOVEMENT OF THE SPECIMEN IN MICROTOMES AND ULTRAMICROTOMES BACKGROUND OF THE INVENTION This invention relates to microtomes and more particularly to an apparatus for an increment movement of the specimen in microtomes and ultramicrotomes;

In microtomes and ultramicrotomes, particularly thin-section and consecutively cutting, rotary microtomes, the specimen is moved up and down past the knife about an axis along an arcuate path or by means of a guide along a straight vertical path. The total vertical movementis predetermined and cannot be adjusted. The movement of the specimen is usually controlled by a drive shaft, which is manually driven either by a handwheel or is motorized. A suitable transmission and connecting linkage is utilized to obtain the vertical movement of the specimen. The connecting linkage consists primarily of levers, to which an oscillating motion in a vertical path is imparted by an eccentric, secured to the drive shaft. The extent of such movement is limited by the eccentric arrangement of the lever on the eccentric and determines the vertical movement of the specimen.

The fact that this vertical movement of the specimen is fixed for an instrument and cannot be changed is undesirable for several reasons. With respect to specimens or structures which are eccentrically disposed in the specimen block, or to particularly large specimens, this movement is, on an average, five to ten times as large as the diameter of the specimens which are usually handled. As a result, the amount of movement is excessive in most cases so that the operation is inefficient and disproportionately slow. Also, the specimen often moves along its path at excessively'high velocities resulting in vibrations at the specimen-knife interface and finally in artefacts which are due to the cutting operation. For this reason, many sections are not usable.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide apparatus which enables adjustment of the vertical movement of the specimen at any time to any degree within a predetermined range. This is accomplished by a rocker having at least two arms between the drive for the vertical movement and the specimen carrier and movable about an axis of rotation with a-bearing carriage adjustable to any position along the rocker and which is adapted to be temporarily locked in any desired position thereon. The distance of said carriage from the axis of rotation controlsthe extent of the vertical movement of the specimen. This arrangement, according to the present invention, results in a great increase of the field of application of such instruments provided therewith and also increases the speed with which a large number of sections can be cut.

According to one important feature of the present invention, the universal adjustment of the vertical movement of the specimen is accomplished by a means which is self-locking or can be temporarily fixed in a desired position. Also, distance or angular graduations provided with a drag pointer or the like provide a check or enable reproducible adjustment of the vertical movement of the specimen.

Further important advantages and features of the invention will be explained more fully hereinafter with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows one simple embodiment of the linkage in a microtome according to the present invention.

FIG. 2 is a side view showing partly in section the arranger'nent of the linkage in a microtome or ultramicrotome.

FIG. 2a is a partly sectional view along lines 22 of FIG. 2.

In FIG. 1, the drive shaft 1 imparts an oscillating or rocking movement by means of connecting member 2 to rocker 3 about the axis 5. This movement is indicated by the double arrow 4. The rocker 3 carries a carriage 7,which is slidably adjustable in a guide 6 to any position along rocker 3. Link 9 is connected to the carriage 7 at pivot 8 for transmitting the vertical movement of the specimen holder (not shown). The adjustment of carriage 7 along the direction of the double arrow 10 can be by hand or by means of a conventional mechanism (not shown) such as a worm gearing, a transmission comprising a wedge-shaped carnwheel, or the like. To ensure that adjustment will be accurately maintained, particularly during the cutting operation, the drive means for performing the adjustment is preferably of the self-locking type. Releasable means can be provided for temporarily locating the carriage 7 on the rocker 3 by a threaded locking member 11.

As shown in FIGS. 2 and 2a, a cam 2a having an adjustable eccentricity may be mounted on the drive shaft 1 and may act directly on the rocker 3 to move the same about axis 12 in accordance with the double arrow 13a. Shaft 13 concentric with the axis 12 carries pinion 14, which cooperates with rack 15 provided on carriage 7. The rocker 3 also carries sleeve 16, in which shaft 13 is mounted. The rocker 3 is supported in one of the two bearings 17 by means of the sleeve 16. To prevent accidental movement of shaft 13 which protrudes beyond the sleeve 16, and thus accidental movements of rack 15, sleeve 16 carries clamp 18 which is secured with screw 19 at the free end protruding from the sleeve 16. Shaft 13 carries a drive means 20', which has a handwheel or knurled wheel and has graduations 21 or the like for reproducible adjustment of the carriage 7 on rocker 3 and an exact check of the position of said carriage 7 relative to the axis 12. The range of adjusting movement-and the vertical movement of the specimen is controlled by. member 22 which is mounted on the carriage 7 and moves inunison therewith in the course of its movement as sho'wn by double arrow 23 until one or'the other of stops 24 are reached.

This arrangement enables adjustment of the vertical movement of the specimen from the outside of the in strument and avoids any opening of the microtome or complicated adjustments of internal elements.

It has proved extremely desirable for adjustability of the vertical movement of the specimen along the nor-' mal path through which the specimen is moved during the normal cutting operations and that the vertical adjustment can be performed without requiring rotation of the drive shaft. As a result, reduction of the vertical movement of the specimen can be fully utilized for eccentrically mounted specimens or if a change of the knife elevation occurs the vertical movement of the specimen can be adjusted without need for a readjustment of the knife or specimen.

It will be understood that the invention is not restricted to the specific embodiments shown and described. Within the scope of the invention, numerous modifications can be conceived without departing from the basic concept of the invention as claimed.

What is claimed is:

1. Apparatus for use in a microtome comprising an elongated rocker member adapted to pivot about an axis, means connected to said drive shaft and adapted to move said rocker member with an alternate motion, an adjustable carriage carried on said rocker member, a linkage assembly pivotably connected to said carriage, said carriage being fixably positionable along said rocker member to regulate the distance traversed by the linkage assembly during the cutting stroke, so that the amount of alternate motion of a specimen holder connected to the other end of the linkage assembly may be adjusted. v

2. The improvement of claim 1 wherein a rack is mounted on said rocker member and a manually operable pinion is rotatably mounted on said carriage and is adapted to engage said rack to slidably move said carriage along said rocker member to provide incremental adjustment of the distance traversed by said specimen holder.

3. The improvement of claim 2 wherein said carriage has a dovetail and said rocker member has a groove adapted to slidably engage said dovetail.

4. The improvement of claim 3 wherein said manually operable pinion has a graduated driving means. 

1. Apparatus for use in a microtome comprising an elongated rocker member adapted to pivot about an axis, means connected to said drive shaft and adapted to move said rocker member with an alternate motion, an adjustable carriage carried on said rocker member, a linkage assembly pivotably connected to said carriage, said carriage being fixably positionable along said rocker member to regulate the distance traversed by the linkage assembly during the cutting stroke, so that the amount of alternate motion of a specimen holder connected to the other end of the linkage assembly may be adjusted.
 2. The improvement of claim 1 wherein a rack is mounted on said rocker member and a manually operable pinion is rotatably mounted on said carriage and is adapted to engage said rack to slidably move said carriage along said rocker member to provide incremental adjustment of the distance traversed by said specimen holder.
 3. The improvement of claim 2 wherein said carriage has a dovetail and said rocker member has a groove adapted to slidably engage said dovetail.
 4. The improvement of claim 3 wherein said manually operable pinion has a graduated driving means. 